Bianchi I meets the Hubble diagram

Abstract

We improve existing fits of the Bianchi I metric to the Hubble diagram of supernovae and find an intriguing yet non-significant signal for anisotropy that should be verified or falsified in the near future by the Large Synoptic Survey Telescope. Since the literature contains two different formulas for the apparent luminosity as a function of time of flight in Bianchi I metrics, we present an independent derivation confirming the result by Saunders (1969). The present fit differs from earlier ones by Koivisto & Mota and by Campanelli et al. in that we use Saunders' formula, a larger sample of supernovae, Union 2 and JLA, and we use the general Bianchi I metric with three distinct eigenvalues.

32 pages, 3 figures. The second version is the published one. Appendix 2 has been omitted, because, although its computations are correct, its final conclusion is wrong and irrelevant

References in corpus (8)

• Spectra and Light Curves of Six Type Ia Supernovae at 0.511 < z < 1.12 and the Union2 Compilation
• Anisotropic Dark Energy: Dynamics of Background and Perturbations
• Testing the Isotropy of the Universe with Type Ia Supernovae
• Cosmic Parallax: possibility of detecting anisotropic expansion of the universe by very accurate astrometry measurements
• Constraining anisotropy of the universe from different groups of type-Ia supernovae
• Cosmic Parallax in Ellipsoidal Universe
• Constraining the Anisotropy of the Universe from Supernovae and Gamma-ray Bursts
• The Hubble Expansion is Isotropic in the Epoch of Dark Energy

Cited by in corpus (3)

• Light propagation in a homogeneous and anisotropic universe
• Testing the isotropy of the Universe with type Ia supernovae in a model-independent way
• Comparison between hemisphere comparison method and dipole-fitting method in tracing the anisotropic expansion of the Universe use the Union2 dataset